The present disclosure relates to vision systems and display of information detected by the vision system.
An aircraft uses a vision system, such as, an enhanced vision system (EVS), to provide imagery to an aircraft crew. The imagery can include an airport terminal area and runway environment when meteorological or lighting conditions prevent a clear natural view of the external surroundings of the aircraft through the windscreen. For example, the EVS may overlay an image of an airport terminal area and runway environment over the pilot's natural unaided view of the external surroundings of the aircraft through the aircraft's cockpit windscreen via a head up display (HUD). Such imagery can improve the situational awareness of the flight crew during instrument approach procedures in low visibility conditions such as fog. The EVS image is often provided to a head up display as a conformal image with the external surroundings.
An EVS often uses a passive sensing system to acquire data used to generate imagery of the airport terminal area and runway environment. A passive sensor, such as, a forward looking infrared (FLIR) camera or visible light spectrum camera, receives electromagnetic energy from the environment and outputs data that may be used by the system to generate video images from the point of view of the camera. The camera is installed in an appropriate position, such as in the nose of an aircraft, so that the pilot can be presented with an appropriately scaled and positioned video image on the HUD having nearly the same point of view as the pilot when viewing the external surroundings of the aircraft through the combiner of the HUD.
Night vision flight rules (NVFR) approaches generally do not use EVS because such systems are often optimized for low visibility operations and have performance limitations during clear NVFR approaches (e.g., black hole approaches).
Thus, there is a need for a system for and method for assisting clear NVFR approaches. Further, there is a need for systems for and methods of providing low cost runway light approach sensing. There is also a need for display systems for and methods of providing EVS sensed information on a head up display (HUD) during night approaches. It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.